Yes, they do work well (the bulk back of Jagwires). I've ordered a bag of them in the past, just to have on-hand for re-doing brakes on my bikes or on project/donation/flip bikes. I have only a few left, but I haven't come across a set of linear pull brakes that needed them in a while, so they may linger! As I recall, the liner even had a dab of grease inside to keep the action smooth. When I do these types of brakes, I leave the rubber boot off -- junk seems to get trapped in those. I just keep the cables wiped dry and nothing seems to stick to them. Those rubber boots can also interfere with smooth braking action if they're long enough to get compressed with the cable pull of normal braking.

Just make sure to not get noodles with modulator springs in them (usually intended for the front brake of entry level bikes intended for novice riders) if you don't want them. I don't commonly see these in the aftermarket, but I imagine they are out there.